This invention relates generally to scintiphotography, and, more particularly, to a patient head restraining device for the vertex brain scan performed by the Gamma Scintillation Camera during scintiphotography.
Scintiphotography is the diagnostic technique by which both normal and diseased organs within a patient can be studied by following the passage of radioisotopes through the organ. This procedure is performed by the use of a Gamma Scintillation Camera such as Nuclear Chicago's Pho/Gamma HP camera which has the ability to visualize the entire organ of interest at one time and to follow the passage of radioisotopes through the organ. Radiation from the radioisotope is rapidly detected and the position and intensity or the gamma events are produced and displayed in a corresponding position on a cathode ray tube display. Time exposures of the gamma image can be taken thereby providing studies of the organ function in both normal and diseased states. A choice of collimators for various resolution and sensitivity requirements help assure meaningful recordings for most clinical situations.
The Gamma Scintillation Camera System is made up of a gamma detector, assembly for supporting the detector and drive motors and controls for detector orientation. Within the gamma detector is a sodium-ioide thallium activated scintillation crystal. The control console is a desk type assembly which contains an XYZ Analyser, timer, display and power supply.
The counting time required to obtain an optimal image of the emission distribution from a patient using a Gamma Scintillation Camera is determined by the amount of the radioactivity administered, sensor sensitivity, lesion uptake and contrast ratio and the ability of the patient to remain still. The longer the time required for the study, the greater is the probability that significant motion artifacts will occur. Studies show that in organ scans the motion artifacts contribute to the deterioration of the quality of the image after a certain interval of time. For example, it has been found that image quality is good up to three minutes of the scan before motion artifacts reduce the useful information that can be obtained from the increased counting rate. Thus, in order to retain high diagnostic image quality in the longer duration studies, it is critical to device improved patient restraining techniques. Heretofore, these restraining techniques ranged from quite cumbersome apparatus, uncomfortable to the patient, such as sand bags, to extremely complicated apparatus utilized to provide adjustability to a variety of shapes and sizes. In addition many of the prior art restrainers produced gamma backscatter during the scintiphotography procedure.